1. Field of the Invention
The present invention pertains to an automated assembly for connecting a fluid flow line to an inlet port. More particularly, the present invention pertains to an automated assembly for connecting a fluid flow line (such as a chiksan, hose or other conduit) to an inlet port of a cement head or hydraulic fracturing (“frac”) head assembly.
2. Brief Description of the Related Art
Many offshore oil and/or gas wells are drilled in marine environments using floating vessels (such as, for example, drill ships and semi-submersible drilling rigs), particularly prior to installation of a permanent platform or other similar structure. Drilling operations conducted from such floating vessels differ from those conducted from permanent structures in many respects.
One important difference associated with drilling from a floating vessel is the location of blowout preventer and wellhead assemblies. When drilling from a fixed platform or other similar structure, a blowout preventer assembly is typically located on a rig, platform or other structure. However, when drilling from a floating drilling vessel, blowout preventer and wellhead assemblies are not located on the drilling rig, platform or other structure; rather, such assemblies are located at or near the sea floor. As a result, specialized equipment known as “subsea” blowout preventer and wellhead assemblies typically must be utilized.
During cementing operations, an apparatus known as a cement head is typically installed above a rig's work surface or “rig floor” in order to provide a connection or interface between a rig's lifting system and surface pumping equipment, on the one hand, and down hole work string and/or other tubular goods extending into a well, on the other hand. Such cement heads must permit cement slurry to flow from a pumping assembly into a well, and should have sufficient flow capacity to permit high pressure pumping of large volumes of cement and other fluids at high flow rates. Such cement heads must also have sufficient tensile strength to support heavy weight tubular goods and other equipment extending from the rig into a well, and to accommodate raising and lowering of such tubular goods and equipment.
Although such cement heads are typically utilized in connection with wells drilled in offshore or marine environments, it is to be observed that such cement heads can also be used in connection with the drilling/equipping of onshore wells using land-based drilling rigs. Furthermore, such cement heads are frequently (although not necessarily exclusively) utilized on onshore and offshore drilling rigs equipped with top drive drilling systems. In certain circumstances, said cement heads are used on rigs equipped with a kelly and rotary table, instead of a top drive unit.
In many cases, such cement heads must be positioned high above a rig floor during cementing operations. In such situations, a fluid conduit must extend from a rig's pumping system (which is typically located at or near the rig floor level) to said elevated cement head. On drilling rigs equipped with a top drive system, it is possible to pump cement and/or other fluids from a rig's pumping system through said top drive unit and a top drive hose extending to a cement head. However, such a configuration is not preferred for cementing operations, because an unexpected loss of power or pumping shut down could result in cement slurry hardening within the top drive unit, top drive hoses and/or ancillary equipment, causing significant damage and/or downtime for such critical equipment.
As a result, a rig's top drive system is frequently bypassed for this purpose and a temporary fluid conduit is typically utilized to connect a surface cement pumping system to the inlet port of a cement head, and to provide cement slurry to said cement head. Such temporary fluid conduit, which can be relatively heavy, can comprise a high pressure hose, a swiveled flow-link apparatus commonly referred to as a “chiksan”, or other flow line(s).
Because a cement head may be located at an elevated location above a rig floor, the distal end or outlet of said fluid conduit typically must also be lifted to an elevated location in order to position it in close proximity to said cement head. Further, such fluid conduit must be securely coupled or connected to a fluid inlet port on said elevated cement head in order to permit pressurized fluid (including, without limitation, heavy cement slurry) to flow through said cement head.
In many instances, a cement head will typically be positioned at an elevated position out of reach of personnel working on a rig floor, thereby making it difficult for such personnel to easily access the cement head in order to connect chiksans, flow lines and/or other fluid conduits to said cement head. Moreover, such personnel often must be hoisted off the rig floor using a makeshift seat or harness attached to a winch or other lifting device in order to reach the cement head for this purpose. When this occurs, such personnel are at risk of falling and suffering serious injury or death. Moreover, such personnel are frequently required to carry heavy hammers, wrenches and/or other tools used to facilitate connection of the flow conduit to the cement head inlet, thereby increasing the risk of such items being accidentally dropped on personnel and/or equipment positioned on the rig floor below.
Further, subterranean hydrocarbon formations are routinely stimulated to enhance their geological permeability and productivity. One common technique for stimulating hydrocarbon formations is to hydraulically fracture a formation by pumping into the well highly pressurized fluids containing suspended proppants, such as sand, resin-coated sand, sintered bauxite or other such abrasive particles. Such fluid and particulate mixtures are commonly referred to as slurries.
During hydraulic fracturing operations these slurries are frequently moved at high pressure from one or more pumps through a pressure containing line to a fracturing head. The fracturing head is typically attached to a wellhead valve secured to the top of the constructed well. The high pressure and typically high fluid flow rates require the architecture of the well head, wellhead valve(s), fracturing head (or “frac head”), connectors, adaptors, conduits, and flanges to be large and robust. High pressure conduits or flow lines conveying the slurry are typically attached at or near the top of the frac head through one or more side entry ports.
In many cases, such side entry ports can be 20 feet or more above the ground or rig support structure. The heavy pressure containing lines must be manually manipulated and attached to the frac head side entry ports prior to pumping. In marine applications, such side entry ports are much higher as consideration must be made for rig heave and movement. Again the heavy pumping lines must be manually manipulated and attached by personnel in a riding harness, lift basket or other device.
Thus, there is a need for a method and apparatus for lifting/positioning of a chiksan or other fluid conduit in proximity to a lifting top drive cement head, as well as secure connection of said chiksan or other fluid conduit to a lifting top drive cement head including, without limitation, when said lifting top drive cement head is positioned at an elevated location above a rig floor. Such lifting and connection should be beneficially accomplished without the need for lifting or raising personnel to an elevated position above said rig floor and/or in close proximity to said cement head inlet.
Further, there is a clear need to eliminate the risk of placing personnel at elevated locations to perform manual labor associated with connection of frac heads, reduce the time needed to connect high pressure conduits to such frac heads, and to eliminate risk of dropped objects. Consequently, there exists a need for a method and apparatus to remotely, efficiently, and safely attach high pressure conduits to such fracturing heads.